Exemplary embodiments of the present invention relate generally to a novel design for a compact, slot-loaded, proximity fed patch antenna structure. While the description herein describes frequency bands that are employed in global positioning system (GPS) implementations for exemplary calculations, the design may be equally applied to other applications where a compact, dual band antenna is desirable.
Global navigation satellite systems (GNSS) such as GPS have become very commonly used devices. Well known uses include automobile and truck navigation systems and military applications. The rapid growth of GNSS technology also includes a growing list of new applications, some examples of which include: vehicle and package tracking, child monitoring, surveying, construction, sports equipment, workforce management, and farming. Along with the growth of applications, there are a growing number of GNSS systems such as GPS (U.S.), GLONASS (Russia), Galileo (Europe), and Beidou (China). Due to this growth, additional frequency bands are being allocated for GNSS use. As a result, GNSS transmitting and receiving electronics, including antennas, may be required to be configurable for a range of frequency channels. There is also an increasing amount of clustering of GNSS channels within these bands. A direct result of this clustering is the need for advanced coding schemes for the satellite signals used by GPS devices, and these advanced coding schemes frequently require wider bandwidth GNSS transmission and reception systems.
In addition to being able to receive a greater number of GNSS channels and having wider channel bandwidths, many GNSS applications require antennas to be small in size in order to fit into the desired device packaging. For example, GPS currently operates using the L1 (1575 MHz) and L2 (1227 MHz) bands. Most existing commercial small L1/L2 GNSS/GPS antennas have relatively narrow 10 MHz bandwidths that are not adequate for supporting advanced GPS coding schemes. Bowtie dipole and spiral antenna designs have been used to achieve wider bandwidth but such designs are relatively large in size and not suitable for small GPS devices. Because of the increasing number of GNSS frequency bands, requirements for wider bandwidths, and a desire for small physical sizes, there is an unmet need for a dual-band, wide bandwidth, and small in size antenna design.
Disclosed herein is an exemplary antenna structure adapted to provide dual band coverage comprising a dielectric substrate layer and a patch layer configured with slots. An embodiment is also disclosed that further comprises a 90 degree hybrid coupler in electronic communication between the patch layer and the signal source feeding the patch layer. Embodiments of the antenna are adapted to utilize both patch and slot modes to produce wide bandwidth and dual band coverage. An additional embodiment of the invention is comprised of a plurality of antennas, each comprising a dielectric substrate layer, and a patch layer configured with slots. An exemplary embodiment may also include a 90 degree hybrid coupler in electronic communication between the patch layer and the signal source feeding the patch layer.
In addition to the novel features and advantages mentioned above, other benefits will be readily apparent from the following descriptions of the drawings and exemplary embodiments.